package com.wu.community.entity;

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

/**
 @author YanGe
 @create 2022-02-22 18:29
 */
@Data
@AllArgsConstructor
@NoArgsConstructor
public class Page {
    // 当前页码
    private int current = 1;

    // 显示上限
    private int limit = 10;

    public void setLimit(int limit) {
        if(limit >=1 && limit <= 100){
            this.limit = limit;
        }
    }

    // 数据总数(用于计算总页数)
    private int rows;

    // 查询路径
    private String path;

    //获取当前页的起始行
    public int getOffset(){
        // current * limit - limit
        return (current - 1) * limit;
    }

    public void setCurrent(int current) {
        if(current >= 1){
            this.current = current;
        }
    }

    // 获取总页数
    public int getTotal(){
        //rows / limit
        if(rows % limit == 0){
            return rows / limit;
        }else{
            return rows / limit + 1;
        }
    }

    //获取起始页码
    public int getFrom(){
        int from = current - 2;
        return from < 1 ? 1 : from;
    }

    //获取终止页码
    public int getTo(){
        int to = current + 2;
        int total = getTotal();
        return to > total ? total : to;
    }
}
